psi: clarify the Kconfig text for the default-disable option
authorJohannes Weiner <hannes@cmpxchg.org>
Fri, 1 Feb 2019 22:21:15 +0000 (14:21 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 1 Feb 2019 23:46:24 +0000 (15:46 -0800)
commit7b2489d37e1e355228f7c55724f77580e1dec22a
tree51ae035f64cbed04a867484904466ca63e044e3a
parente3df4c6e4836ce93cd5cf92d9cbdeaf4439a0241
psi: clarify the Kconfig text for the default-disable option

The current help text caused some confusion in online forums about
whether or not to default-enable or default-disable psi in vendor
kernels.  This is because it doesn't communicate the reason for why we
made this setting configurable in the first place: that the overhead is
non-zero in an artificial scheduler stress test.

Since this isn't representative of real workloads, and the effect was
not measurable in scheduler-heavy real world applications such as the
webservers and memcache installations at Facebook, it's fair to point
out that this is a pretty cautious option to select.

Link: http://lkml.kernel.org/r/20190129233617.16767-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
init/Kconfig